Spark plug and electrode therefor



Dec. 25, 1945. R; HENSEL SPARK PLUG AND ELECTRODE THEREFOR Filed May 2, 1944 f 'INVENTOR.

7 #2 iii/final nrrox/vzr conductivity and a sheath.

- found: that j particular value by virtue of 'abl'e' factors, among which-the co-efiicients of thermal expansion ,of these frna tepansion of the order .of, about 16 exhibit valuable tagefs not only in the use but; also in the manufac- '1 above' These temperature below about 900 metallic wiresuitable f or the spark plug electrodes contemplated itic compositions suitable nickel;

-the balance chiefly plated to use composite materials dingconsists of cobalt or chromium basejcompositions, platither contemplated to fabricate the. loop from tungsten base alloys j or buttweldingit-irom wire and then electroplat- 2 welding, brazing or any other suitableioini'ng method. Alternatively, the loop electrodes according to this invention-may beprepared by -pdvvd'er nietallurgical methods or any other-suitablemanuiacturing procedure. While the electrodes of the spark plug contem-v plated by suitable material, either one or both the I ofa core I' I. (see Fig. 2) formedioifia 'metallic.1. composition having a high thermal and electrical l8; of a metallic comi position having a relatively high meltingpoint and characterized by a high resistance 'topitting, oxidatiom corrosion:and erosion. Ithas. been a combinationfof il') copper and/or silver compositions for the coreand (2) austenitic iron alloys -for the sheath of ,the electrodesis of a numberof favorthis invention may-*be-iormed oi any in a preferred embodiment closely matching;

"rials. For example, the commonlykn'own austenitic nickel steels, nickel-chromium steels, man-g ganese steels, etc., have coefiicients of. thermal'exto121 10:, the

corres riding values forcopper; andlsilver being 17)(1 andl8'or 19.xl0:, respectively. 1 In addition,-austenitic ferrous alloysxahd steels anti-corrosiveproperties, and are, furthermore characterized by; e cellent capaci I ties for plastic deformation which, in some cases almost parallel those of copper and silver. Hence the combination of theshe th and core materials contemplated by this invention: results in advan -l 'ture of the'bi-metallic electrode structures.v For example, it is possible to firstproduce a wire bar of any of the austenitic *materials mentioned bars may then be hot rolled at any C. to producea biby this invention. It is also' possible toreduce the'cross-section by cold rolling, which process simultaneously hardens the austeniti'c'- case material to an appreciable extent.

The following are a nurnber-:of,;typic al a'u'sten v for sheath rnaterials as contemplated'by this invention: Austeniticsteels containing in additionto the usual carbon content from about 14% to-about- 36% of one or more of the elements chromium, nickel, manganese, typical examples of these being (a), a stainless steel containing about 18% chromium and 8%; (b) 'a steel containing '.about24;% nickel and the balance chiefly iron; (0) a steel contain- I ing about'14% manganese, aboutl% iron. In, addition to 'a'ustenitic steels itis contexnr 6 0- pure nickel or high nickel alloys,

num and/or palladium and their alloys, Itislfur j 65. tungsten by hot punching from strip or from high g by apply ng powder. metallurgical methods. 1 J 1 1 It is further; contemplatedto ,producecomflrs't'punching. the corez from strip ing the core material with nickelor platinum group metals n s ulatorjanda rod. portio'ngo i to atleast one rod comprisingthe other 'eliactrcpde;or said;plug.

expa ion. fl i jj-" 1 Spark plug; electrode as .01

1 in which said; core is'iorrnedotfcopper 1 said; Sheath is ,formed of auste'nitic steels ctrode asclaimed'in in which saidlcoreis iormed'ot silver.;wire, and said sheath is'madeof austenitic-chromium nickel having a core of copper or slver and a cladding. a -v 1. 4o:v HT

, one of themet er an austeniticj'alloy of iron. I

fnsp k plug having a; central-'metal'spindle terminating ina closed loop 5. Spark plug ele carbon. and 1 where the clad- T'cdnsisun or copper Y .10 A ,-spark;.plug, I vactive sparking portion-thereoMormedot' an aus- Ateniticiron alien? group metals.

While-the invention, vantages, zhas-been desc tozspecific "embodiments thereohit to be limited-thereby, the invention broadly,

of-the appended claims. l

l. A-spark plug, comprising a'passagejtherethrough, a center extending through of saidelectrode, being formed in its axis perpendicular to said and alloys or rhenium ortungsten as .to. its objects and adbed herein as applied I V v is anotdesired b t itisE-intended tocover within the anlinsulator having electrode spindle said passage, the sparkingend' the shape of a spindle, a conductive shell surrounding said inating proportions o copper and silver, an zalterialfjcomprising pr an Lass whi o i es.

steel;

u 6.YA spark plug electr'ode comprising ,sfubstantialangleto $8,111 spindle, said: 7 prising the center electrode'ofsaidplug", and a side electrode comprising a rod extending through the f.- ,saiq,loop.;

peripheralc1 least one or said l'gap d'e flning'f p isesajco reof a material consistingof predomif at fleast .bn dfthepmetals d a sheath orcase ofa maedom'inatinsl proportions-o! ni fim Q1 W I l 31Afsparkplirg p plus'hav'm 'a terminating" in,

i '7 central and being integrally :united oint of said shell,?said lined in vclaim; 1 ,in' svhich electrodes-comelectrode; at a iot 'cbre of electrically highly sheath oEan= austenitic cient' 'oi thermal 't saidcore mateinsecure a and claim 3 loop comcentral metal spindle,

a closed'loop having its axis at a Substantial angle to". Said spindle, j said 160p comprising the center'electrode oi;

electrode comprising airodextendingthrough 7 said plug,*-and a consisting of, copper and s lver and a sheath enclosing and bonded to-said coreifsaid sheath being formed of an core .;A, ar1s muesliode; v igh.conductivity-metal se1ectpdfrom;the group austeniticiron alloy 5 cient o1, enpansion appronirnating thatooi said cdmprisingla core of dsilveri and al 1 ",closingand bonded to said'core, said sheath :beinfl havinsacoemelectrodel havin z 'at-least the spirit and scope a-Rcore of alsf copper and silver, and a sheath manor said 

